High Density Liquid Crystalline DNA

A gradual transition from blue to green shades in the focal conic texture of this liquid crystalline DNA specimen are indicative of a progressive thickness gradient. Note the yellow and blue bands in some portions of the texture, which are evidence of a variation in the molecular organization of the mesophase. The DNA concentration for this specimen is approximately 400 milligrams per millimeter, and the magnification is approximately 200x. The digital image presented above was originally recorded on Fujichrome 64T transparency film using a Nikon Optiphot-Pol microscope with crossed polarized illumination. Exposures were recorded about 2.5 f-steps under the recommended value given by an in-camera photomultiplier and were push-processed approximately 1.5 f-steps in the first E-6 developer.